It is the long range goal of this project to study the inactivation of prostaglandins by the lungs and other tissues. The effect of environmental agents on the pulmonary transport and metabolism of prostaglandins is being investigated, and these effects are being related to pulmonary toxicity and damage caused by the environmental agents. Topics of current interest are the structural requirements of a prostaglandin needed for transport to intracellular spaces. The isolated perfused lung preparation is being used extensively in these studies.